1. Field of the Invention
Aspects of the present invention are directed to sharing information. More particularly, aspects of the present invention are directed to sharing information content without revealing the source of the information.
2. Background Art
In a growing number of situations, security is becoming an issue with information sharing. One may want to share information about a topic but not reveal the source of the information. For instance, an individual in a government agency may have a confidential document that contains information relevant to an inquiry made by another at a different government agency. Because of security concerns (including revealing the document or its source), the individual with the document is prevented from sharing this information with the other individual even though the other individual may have a clear need for the information.
Existing approaches to sharing information may be grouped into two classes: “system high access” security approaches and multi-level approaches. In “system high access” approaches, all users have access to all information. This approach has the virtues of simplicity and maximal access to information. However, it is relatively poor from the standpoint of the security of the information.
In multi-level security approaches, information of interest is divided” into compartments. Individual users have access only to specific compartments. Compartmenting information through multi-level security has several drawbacks. Fundamentally, a problem exists of having to implement a computer system that can be trusted to genuinely provide multi-level security. The complexity of modern operating systems makes such an implementation a difficult task. Even if that problem is solved, the multi-level security approach has many of the same problems as the “system high” approach. If few users have access to multiple compartments, the degree of information sharing is minimized. This approach significantly enhances security, but at a cost of much more limited use of the information. However, if many users have access to multiple compartments, security is compromised. In the limit, as many users have access to many compartments, the multi-level security approach resembles a “system high” implementation.
Queries made by an individual for information may be in electronic form. This may be due to the large volume of information to be parsed or because of the anonymity electronic searching can provide. Adding to the difficulties of electronic searching are the differences between organizations that provide information. These organizations may use different terminologies, different methods of organizing data, and have different priorities in their indexing systems. Further, language issues may arise as well as name variations, transliteration differences, nicknames, and aliases. Finally, one entity may relate two concepts while another may not. The combination of these factors lead to greater hurdles in attempting to exchange information between organizations. One text has referenced multiple users working together to share limited bits of information, one at a time. To implement this approach, one would need to distribute all information from all users to all other users, which would be a significant load for multiple users with large amounts of data (Schreier, B., Applied Cryptography, 2nd Edition, John Wiley and Sons, 1996, p. 529. ).
An approach is needed that permits electronic searching for information while providing a strong level of security for participants.